1. Field of the Invention
The present invention relates to portable terminals, and more particularly, to a multi-standby portable terminal that can receive different radio frequency (RF) signals from a plurality of RF communication networks.
2. Description of the Related Art
In general, portable terminals typically refer to electronic devices that allow users to freely enjoy wireless communication, which may comprise, for example, radio frequency (RF) communication, network access, digital broadcast reception, etc. As portable terminals are very popular and widely used, manufacturers have developed these terminals so as to provide a variety of functions.
In recent years, multi-mode portable terminals have been released on the market, which can use two or more RF communication networks. The multi-mode portable terminals can perform RF communication within at least two or more RF communication network service areas. For example, dual mode portable terminals can support a Code Division Multiple Access (CDMA) network and a Global System for Mobile communication (GSM) network, so that they can perform communication within both CDMA and GSM network service areas. The multi-mode portable terminals are, however, disadvantageous in that, since as they switch among communication networks in such a way that they are booted, enter an idle mode, and then perform a switching operation by operating a menu prior to the actual switch. In addition, the switching process of these terminals is often complicated to operate and require a lot of time to switch their modes.
In order to resolve these problems in the multi-mode portable terminals, a conventional multi-standby portable terminal has been proposed to attempt to address some of these problems. For example, unlike the dual-mode portable terminals described above, a dual standby portable terminal can simultaneously support two networks, for example, a CDMA network and a GSM network. This conventional dual standby portable terminal periodically requests and receives a preamble and/or pilot channel signal from base stations for both CDMA and GSM communication networks, respectively, even during the idle mode, and measures the channel states, such as RSSI, CINR, SoQ, etc., so that it can simultaneously support two communication networks.
The conventional multi-standby portable terminal includes a plurality of different antennas in its single body to be able to transmit and receive at the various frequencies assigned to the different wireless protocols. However, the conventional multi-standby portable terminal suffers from the fact that it cannot completely isolate one antenna from among the different antennas, so these antennas interfere with each other, and thus the communication performance of the portable terminal is deteriorated.
Therefore, there is a long-felt need in the art to provide a new multi-standby portable terminal that minimizes interference among antennas installed therein and to accordingly optimize their communication performance.